Planar optical waveguides with planar optical elements

Abstract

A planar optical waveguide comprises a substrate 1, a waveguide core layer 2, at least one planar optical element, wherein said planar optical element comprises at least one optically functional interface 3 which is adjacent to a cavity 4, and an overclad layer 5. The cavity enhances the optical characteristics of the planar optical element because of the substantial difference in the refractive index of the cavity as compared to the refractive index of said waveguide core layer.

I claim: 
     
       1. A planar optical waveguide, comprising (a) a substrate,   (b) at least one region of optically transmitting core material combined with said substrate to form a planar structure,   (c) at least one planar optical element formed in said of optically transmitting core material, wherein said at least one planar optical element comprises at least one optically functional interface and a cavity in said region of optically transmitting core material, said at least/one optically functional interface being adjacent to said cavity, said cavity containing air or being evacuated such that the refractive index of said cavity is substantially different than the refractive index of said at least one region of optically transmitting core material, and   (d) a region of overclad material applied over said at least one region of optically transmitting core material and said at least one planar optical element.   
     
     
       2. The planar optical waveguide of claim 1 wherein said at least one planar optical element is a lens. 
     
     
       3. The planar optical waveguide of claim 1 wherein said at least one planar optical element is a microprism. 
     
     
       4. The planar optical waveguide of claim 1 wherein said at least one planar optical element is a grating. 
     
     
       5. The planar optical waveguide of claim 1 wherein said at least one planar optical element is designed such that said planar optical waveguide functions as an M×N coupler, with M and N being integers. 
     
     
       6. The planar optical waveguide of claim 1 wherein said region of optically transmitting core material comprises silica or doped silica glass. 
     
     
       7. The planar optical waveguide of claim 1 wherein the difference between the refractive index of said at least one region of optically transmitting core material and that of said at least one planar optical element is greater than about 0.04. 
     
     
       8. The planar optical waveguide of claim 7 wherein the difference between the refractive index of said at least one region of optically transmitting core material and that of said at least in planar optical element is in the range of about 0.04 to 2.0. 
     
     
       9. A planr optical waveguide, comprising (a) a substrate,   (b) at least one region of optically transmitting core material combined with said substrate to form a planar structure,   (c) at least one planar optical element formed in said region of optically transmitting core material, wherein said planar optical element is characterized by a refractive index which is substantially higher than the refractive index of said region of optically transmitting core material; and   (d) a region of overclad material applied over said at least one region of optically transmitting core material and said at least one planar optical element.   
     
     
       10. The planar optical waveguide of claim 9 wherein said at least one planar optical element is designed such that said planar optical waveguides functions as an M×N coupler, with M and N being integers. 
     
     
       11. The planar optical waveguide of claim 9 wherein the difference between the refractive index of said at least one region of optically transmitting core material and that of said at least one planar optical element is greater than about 0.04. 
     
     
       12. The planar optical waveguide of claim 11 wherein the difference between the refractive index of said at lest one region of optically transmitting core material and that of said at least on planar optical element is in the range of about 0.04 to 2.0. 
     
     
       13. The planr optical waveguide of claim 9 wherein said region of optically transmitting core material comprises silica or doped silica material. 
     
     
       14. The planar optical waveguide of claim 9 wherein said planar optical element is a lens. 
     
     
       15. A planar optical waveguide, comprising (a) a substrate,   (b) at least one region of optically transmitting core material combined with said substrate to form a planar structure, and   (c) at least one palanr optical element formed in said region of optically transmitting core material, wherein said planar optical element is characterized by a refractive index which is substantially different from the refractive index of said region of optically transmitting core material, wherein said cavity contains doped-silica glass or other high refractive index material such as silicon nitride, silicon oxynitride, or amorphous silicon such that the refractive index of said planar optical element is substantially greater than about 1.5, and the refractive index of said at least one region of optically transmitting core material is substantially less than about 1.5.